From
FAQ:
What is XviD?
XviD is an ISO MPEG-4 compliant video codec. It's no product, it's an open source project which is developed and maintained by lots of people from all over the world.
XviD
DirectShow and
VFW frontends were base for ffdshow - instead of reading
DirectShow documentation I used already existing simple and easy understandable code.
And additionally to being nicely written, XviD is probably the highest quality MPEG-4
? encoder available.